Thesis (doctoral)--Université Paris VII-Denis Diderot, 1998. / "Lille-thèses, ISSN, 0294-1767"--Fiche header.

No description available.

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 331-349).

Thesis (Ph. D.)--University of Sydney, 2008. / Title from title screen (viewed 19 January 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Veterinary Science. Degree awarded 2008; thesis submitted 2006. Includes bibliographical references. Also available in print form.

Contagious caprine pleuropneumonia (CCPP) is a highly contagious disease that affects goats in Africa and Asia resulting in great economic losses. The aetiological agent is Mycoplasma capricolum subsp. capripneumoniae (Mccp). It belongs to a group of organisms that are all associated with economically important diseases of ruminants and all exhibit similar genetic and antigenic characteristics. The diagnosis of CCPP has often been considered difficult due to confusion with other mycoplasmas of ruminants and the limited specificity of most diagnostic assays. It is therefore important to improve diagnosis and thereby the control of CCPP. Two approaches, namely phage display and anti-idiotype antibodies can be used to identify antigenic mimics with the potential to be used in developing new vaccines, diagnostic methods or therapeutics. Both were used in an attempt to generate surrogate antigens for Mccp. A monoclonal antibody (Mab) or its F( ab ')2 fragments directed against Mccp membrane protein epitopes was injected into hens to induce the production of anti-idiotype antibodies. The antibodies produced were functionally able to mimic the epitope recognised by the Mab since they inhibited binding of the Mab to mycoplasmal lysate. Mice were also immunised with the Mab and or F(ab') 2 fragments of the antibody. The resulting antisera were tested in ELISA, but no significant response was detected. The selection of peptides from a random epitope library displayed on the surface of filamentous phages was used to characterise the epitope recognised by the Mab. Two different, but related peptides were identified that reacted with the antibody in enzyme-linked immunosorbent assays (ELISA). Binding to the Mab was further characterised by surface plasmon resonance. Sequence analysis revealed that the two peptides each had a cysteine residue in addition to the one fixed in amino acid position 2 as well as identical or similar amino acid residues in positions 5 (P), 8 (I/L) and 13 (L). One of the peptides had 74% similarity with an amino acid sequence of the PG 1 strain of Mycoplasma mycoides subsp. mycoides SC. The peptides as well as the anti-idiotype antibodies were not detectable using Mccp-specific goat antiserum suggesting that the serum did not contain paratopes that could accommodate the surrogate epitopes. In spite of this, the antiserum efficiently inhibited the binding of the Mab to immobilised mycoplasmal lysate in a standardised test for Mccp antibodies. This assay therefore appears to depend on a structural, rather than a functional blocking of the epitope which the Mab recognises. The findings in this study have elucidated some of the characteristics of the Mab and raised the possibility that the epitope recognised by the Mab is not immunodominant. Peptides identified by phage display and chicken/murine anti-idiotype antibodies, nevertheless, have the potential of being used as antigens in immunoassays aimed at CCPP diagnosis. In light of the results generated it would therefore be necessary to investigate other Mabs or polyclonal antiserum in order to yield antibodies or peptides of the desired specificity. / Dissertation (MSc (Microbiology))--University of Pretoria, 2007. / Microbiology and Plant Pathology / unrestricted

Social animals, such as primates, incur many fitness-related costs as a direct result of living in groups of conspecifics. However, group-living also comes with benefits. Sociality is thought to have evolved in response to the need for individuals to negotiate their social environment in order to maximise the benefits and minimise the costs associated with group-living. Recently, researchers interested in animal sociality have turned to a set of sophisticated statistical tools, collectively termed 'social network analysis' in order to better understand the structure of animal social systems and the role of individuals within their social groups. Using a social network analytic approach, I explore the relationship between the ecological and social environments, and the implications of an uncertain social landscape for individual fitness and fitness-relevant processes in two species of Old-World monkeys: chacma baboons (Papio hamadryas ursinus) and vervet monkeys (Chlorocebus aethiops pygerythrus). My results suggest that individuals respond to fluctuating local conditions in diverse ways depending on behavioural context and their current reproductive state, and that the social environment experienced by an individual, and their active pattern of social engagement has important implications for infant survival. Finally, I investigate how network structure influences two fitness-relevant processes of flow in a population of vervet monkeys: information transfer and disease transmission. I conclude that the complex social life of animal groups emerges from many individuals trying to achieve the same fitness goals. Successful individuals exploit the complexity in their social environment and respond adaptively to an uncertain and inconstant set of local conditions by actively adopting social strategies that serve to enhance their fitness.

Various natural environments have been examined for the presence of antibiotic-resistant bacteria and/or novel resistance mechanisms, but little is known about resistance in the terrestrial deep subsurface. This study examined two deep environments that differ in their known period of isolation from surface environments and the bacteria therein. One hundred and fifty-four strains of bacteria were isolated from sediments located 170-259 m below land surface at the U.S. Department of Energy Savannah River Site (SRS) in South Carolina and Hanford Site (HS) in Washington. Analyses of 16S rRNA gene sequences showed that both sets of strains were phylogenetically diverse and could be assigned to several genera in 3-4 phyla. All of the strains were screened for resistance to 13 antibiotics by plating on selective media and 90% were resistant to at least one antibiotic. 86% of the SRS and 62% of the HS strains were resistant to more than one antibiotic. Resistance to naladixic acid, mupirocin, or ampicillin was noted most frequently. The results indicate that antibiotic resistance is common among subsurface bacteria. The somewhat higher frequencies of resistance and multiple resistance at the SRS may, in part, be due to recent surface influence, such as exposure to antibiotics used in agriculture. However, the HS strains have never been exposed to anthropogenic antibiotics but still had a reasonably high frequency of resistance. Given their long period of isolation from surface influences, it is possible that they possess some novel antibiotic resistance genes and/or resistance mechanisms. Seven of the strains from the HS that are resistant to tetracycline were examined for the presence of a novel antibiotic resistance gene. From these seven strains, a novel tetracycline resistance determinant was characterized. The predicted amino acid sequence shares only a 30% sequence similarity with TetA(Z), the most closely related previously described determinant. The new protein is a putative efflux pump with several characteristics in common with previously characterized efflux pumps including: a divergently transcribed TetR repressor, conserved GxxSDRxGRR motif, and transmembrane domains. The determinant has been assigned the name Tet 42. Functional genes from another subset of 11 HS strains that are resistant to ciprofloxacin were sequenced for resistance-conferring mutations. The most common mechanism of resistance to this antibiotic is based on mutations in the functional genes for DNA gyrase (gyrA, gyrB) and topoisomerase II (parC, parE). Sequences for the genes gyrA, gyrB, and parC in resistant strains were compared to the same sequences from ciprofloxacin-sensitive strains from the HS and Escherichia coli. The strains grouped into three genera: Arthrobacter, Sphingomonas, and Pseudomonas. All of the resistant strains possessed some mutations in their gyrase and/or topoisomerase genes that result in the substitution of amino acids not seen in the gene products of E. coli and the sensitive strains. These mutations, some of which have not been reported previously, can be considered putative resistance-conferring mutations. The resistant subsurface strains were also grown in the presence of an efflux pump inhibitor, and a majority of the cultures did not grow when the inhibitor was added. Lack of growth in the presence of the inhibitor may indicate that ciprofloxacin resistance is due entirely or in part to an efflux pump. The presence of an efflux pump might also explain why some of the strains with a higher minimum inhibitory concentration (MIC) have fewer mutations in their gyrase and/or topoisomerase genes than do strains with a lower MIC. It is possible that, along with novel mutations that may play a role in resistance, these strains also posses an uncharacterized efflux pump. A third approach used in this study to examine novel antibiotic resistance mechanisms was to look at differences in the entire proteome under normal and stressed conditions. The strain G887 is resistant to tetracycline and possesses the tetracycline resistance determinant Tet 42. Cultures of this strain were grown with tetracycline and without tetracycline. Protein extractions were performed from each culture and separated in the 1st dimension according to pI, on 4-7 Isoelectric Focusing Strips (IEF) strips and 6-11 IEF strips. After the 1st dimension separation, the proteins were separated by molecular weight on 12% acrylamide gels. The gels were stained with a fluorescent stain, imaged, and analyzed with spot analysis software. The gels run with the proteins from the tetracycline-treated culture indicated that several proteins visualized on both the 4-7 and 6-11 gels were upregulated in the presence of tetracycline. Some of these spots correspond to the molecular weight and pI for Tet A(42) or to those of several previously described general stress proteins. This work demonstrates that there is a high frequency of antibiotic resistance in the deep terrestrial subsurface and that bacteria in this environment possess uncharacterized antibiotic resistance genes and mutations that confer resistance. Given the constant emergence of antibiotic-resistant pathogenic strains in clinical settings and the problems this creates with respect to the treatment of bacterial diseases, it becomes increasingly important to characterize antibiotic resistance genes that may exist in the environment but have not yet been transferred to clinically important species. Our ability to alter existing antibiotics or develop new drugs to counter novel resistance mechanisms will be dependent on such characterizations. It might also be worthwhile to investigate subsurface bacteria for the ability to produce antibiotics themselves. There is a real potential for novel antibiotic discovery, given the length of time these bacteria have been isolated from antibiotic-producing bacteria in surface environments. / A Dissertation submitted to the Department of Biomedical Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2008. / October 3, 2008. / Antibiotic Resistance, Bacteria, Subsurface / Includes bibliographical references. / David L. Balkwill, Professor Directing Dissertation; Hank W. Bass, Outside Committee Member; Graham A. Patrick, Committee Member; Branko Stefanovic, Committee Member.

Master of Public Health - MPH / Non-Communicable Diseases (NCDs) are some of the leading causes of death worldwide. Obesity results from the interactions between biology, behaviour, and environment. The current obesity epidemic is largely driven by environmental rather than biological factors, through its influence on social norms regarding food choices and lifestyle behaviours. The number of people dying from diabetes and hypertension keeps increasing because of the current obesity trend.

In this research, three methods of aerosol generation, and their subsequent propagation, are investigated experimentally. These experiments provided insight into the potential risk aerosol can have pertaining to the spread of infectious disease such as COVID – 19. The first of which investigated an alternative generation route that may exist given the discovery of small numbers of viable viruses in urine and stool samples. Flushing biomatter can lead to the aerosolization of micro-organisms; thus, there is a likelihood that bioaerosols generated in public restrooms may pose a concern for the transmission of COVID-19, especially since these areas are relatively confined, experience heavy foot traffic, and may suffer from inadequate ventilation. The results indicate that the particular designs tested in the study generate a large number of droplets in the size range 0.3 𝜇𝑚 – 3 𝜇𝑚, which can reach heights of at least 1.52 m. This highlights the need for incorporating adequate ventilation in the design and operation of public spaces, which can help prevent aerosol accumulation in high occupancy areas and mitigate the risk of airborne disease transmission. Secondly, experiments were conducted to evaluate the effectiveness of facial coverings at various distances around a simulated cough. These concluded that due to the gaps along the seal of a face mask, aerosols can escape 360° around a coughing individual. In the final portion of the thesis study, an experimental method was developed and conducted to break up a droplet via mechanical excitation. The results of these experiments showed that when a droplet is placed on a vibrating string, the droplet can be broken into many secondary droplets which is analogous to one speaking or singing thus providing insight as to how vocal cords can generate respiratory aerosols. / Includes bibliography. / Thesis (MS)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection